The present application relates to a magnetic recording medium which uses a base material which has flexibility.
Magnetic recording media which are used for a hard disk drive (referred to below as a “HDD”) are generally classified into in-plane magnetic recording media and perpendicular magnetic recording media according to the method of arranging the recording magnetization. From the viewpoint of increasing the recording density, perpendicular magnetic recording media have an advantage compared to in-plane magnetic recording media.
In a perpendicular magnetic recording medium, the easy axis of magnetization of magnetic body microcrystals inside a recording layer is oriented so as to be perpendicular with respect to a substrate. In order to increase the recording density, it is important to orient the easy axis of magnetization of the magnetic body microcrystals so as to be properly aligned in the perpendicular direction.
Japanese Unexamined Patent Application Publication No. 2008-287808 (refer to paragraph [0054]) discloses that, in a magnetic recording medium for an HDD, Δθ50, which is an index of orientation dispersion, is suppressed to approximately 3 degrees by suppressing the orientation dispersion of the easy axis of magnetization of magnetic body microcrystals in a perpendicular recording layer.